Method and device for generating electrical signals corresponding to a wavelength, from polychromatic optical signals

A method is provided for generating a plurality of electrical signals from polychromatic optical signals extracted from a set of optical fibers, a polychromatic signal including a plurality of predetermined wavelengths. An electrical signal is generated by using predetermined wavelengths. The method includes: grouping the extracted optical signals together into a polychromatic optical signal beam; separating the polychromatic signal beam into a plurality of monochromatic optical signal beams; and converting the plurality of separated monochromatic optical signal beams into the plurality of electrical signals.